Common Questions - Diagnostic Tests

Common questions, with answers about diagnostic tests for sarcoidosis, by the late Dr. Om P. Sharma.

106. What is a gallium lung scan?

The test is done by injecting a radioactive substance, gallium-67, into one of your veins. The gallium then is picked up by the organs affected by sarcoidosis and other inflammations. Two days after, the body is scanned and pictures are obtained to see the extent and severity of sarcoidosis. The test is not routinely performed in every patient. Discuss this with your doctor.

107. What is bronchoalveolar lavage?

A bronchoscope is a long, narrow tube with a light at the end. It is used to examine the breathing tubes and the lungs. It is also used to collect fluid from the lungs. This fluid is examined for various cells and substances that reflect the inflammation and immune changes in the lungs. This process is referred to as bronchoalveolar lavage (BAL).

108. What is a lung biopsy?

This procedure consists of removing a tiny piece of the lung tissue in order to examine it under the microscope. This is the single most important test in correctly diagnosing your lung disease.

109. How often a sarcoidosis patient should have a T8 test and a Gallium Scan?

Gallium is performed to study the extent and activity of sarcoidosis. It may be used to assess the response of the disease to treatment. A tuberculin (T81 test is performed initially when the sarcoidosis patient is investigated in order to exclude tuberculosis.

110. I have never had a gallium scan should I?

No, not if you do not have any symptoms and your physician does not feel a need for the test.

111. When is a mediastinoscopy indicated?

If a patient has enlarged glands in the mediastinum and the chest, and the diagnosis has not been established by transbronchial lung biopsy, then a mediastinoscopy is indicated.

112. What tests are there for predicting disease activity in sarcoidosis?

Chest x-ray film, lung function tests, serum angiotensin converting enzyme, serum calcium and Gallium-67 scan and lymphocytes in bronchoalveolar lavage are some of the tests used to assess activity.

113. How useful is the serum angiotensin converting enzyme (SACE) test?

Serum ACE level is high in about 60% of the patients with active sarcoidosis. ACE level comes down when the disease undergoes remission or responds to treatment. There are other conditions that also may have high ACE levels including milary tuberculosis, leprosy, coccidioidomycosis and lymphoma. Some patients with chronic fatigue syndrome (CFS) may also have high serum ACE levels.

114. What is the single most specific test to diagnose sarcoidosis?

The best way to diagnose sarcoidosis is to obtain a tissue biopsy and demonstrate the presence of noncaseating granulomas, excluding any other causes of the granulomatous reaction including tuberculosis, histoplasmosis, coccidioidomycosis, and berylliosis.

115. If a person does not have sarcoidosis and is injected with the Kveim antigen, is there any concern that this person could later develop sarcoidosis?

No.

116. Is Kveim-Siltzbach test FDA approved? In this day and age of AIDS is the test safe?

Kveim-Siltzbach is not approved by the FDA. The test is safe; however, the antigen is not available.

117. What medicines are used for treating of sarcoidosis?

The most commonly used drugs are corticosteroids (cortisone, prednisone, methylprednisolone). Many physicians use chloroquine, hydroxychloroquine (used in the treatment of malaria) and immunosuppressive drugs (methotrexate, azathioprine, cyclophosphamide, chlorambucil). Many of these drugs are not approved by the FDA in the treatment of sarcoidosis, but they are used. Anti-tumor necrosis factor drugs namely infliximab, etanercept, thalidomide, and pentoxifylline are used in selective cases.

118. How do I know if my disease warrants corticosteroids (prednisone, cortisone) treatment?

Your physician in consultation with a sarcoidosis specialist will determine the extent and severity of sarcoidosis and advise accordingly. In general, severe shortness of breath, irregular heart rate, heart block, red eyes and nervous system involvement, extensive skin lesions warrant treatment with corticosteroids.

119. What is a High Resolution Computerized Tomography (HRCT)?

HRCT is a special radiological test that uses a computer program to find severity and extent of lung disease.

120. Are HRCT and CT examinations the same?

No, HRCT is more refined and commonly used for sarcoidosis, interstitial lung disease, emphysema, and bronchiectasis. Usually the CT scan with contrast is used to diagnose lung cancer.

121. What is thoracoscopic lung biopsy?

It is a procedure to obtain a lung biopsy specimen without opening up the chest wall. The biopsy is obtained through three tiny holes in the chest. It is less invasive than an open lung biopsy.